Shandong Zaozhuang started 2016 “One Machine, Two Devices and Four Meters” special measurement inspection

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[China Instrument Network Instrument Industry] March 11th, in order to strengthen the measurement of fuel dispensers, taximeters, scales, and water meters, electric energy meters, heat meters, and gas meters (hereinafter referred to as "one machine, two devices, and four meters") To supervise and manage and effectively safeguard the legitimate rights and interests of the people, the Zaozhuang City Supervision Bureau of Shandong Province will organize and carry out the 2016 “One Machine, Two Instruments and Four Meters” special measurement inspection.

This special inspection will adopt a combination of “one machine, two devices and four tables” and self-examination by the unit and spot check by the departments. Whether or not a user unit establishes rules and regulations for strengthening the management of compulsory inspections and measurement instruments and seriously implements it, and whether it will be mandatory Registered measuring instruments for registration, and apply for compulsory measurement verification to the metrological verification agency to which the metrological administrative department belongs or authorized; whether there are measurement instruments that have not been used for verification, exceed the verification period, or have failed the verification; whether there is damage to the measuring instruments Whether the use of measuring instruments for measurement cheating or other measurement violations is inspected, the problems found in the inspection will be based on the "Measurement Law" and "Management Measures for the Verification of Work Measuring Instruments Compulsory Verification by the People's Republic of China" "Refueling." The measures for station metrology supervision and management are strictly punished.

In order to promote the smooth implementation of special inspections, the city supervision bureau organized relevant sections to hold special meetings, formulated practical work plans, defined the work content and time limits, decomposed the tasks into specific departments, and requested that the departments cooperate with each other. Resource sharing ensures that inspections are effective.

4 Layer PCB

4 Layer PCB

What is 4 layer PCB?

Four-layer circuit board is a kind of printed circuit board. It is made of four layers of glass fibre, which can reduce the cost of PCB.

Compared with Double Sided PCB, multi-layer PCB have many advantages. They can be designed more compactly. They can greatly improve noise resistance and make layout easier.


There are also great differences between the 2-layer and 4-layer PCB. For details, please click: What's the difference between 2 layer and 4 layer PCBs?




4 layer PCB stackup and thickness


4 layers PCB stackup


4 layer PCB stackup


4 layer PCB stackup include two inner layers, inner layer 1 and 2, are sandwiched between the top and bottom layers. From top to bottom, the 4-layer PCB stackup like below ,The top, i.e. the signal layer (0.0014 in. width) is followed by a prepreg layer with a thickness of 0.0091 in. and dielectric constant of 4.2. The top layer is copper material. The prepreg layer is followed by inner layer 1 (0.0014 in.), referred to as the plane. A core sublayer is part of inner layer 1, which has a width of 0.037 in. This is followed by inner layer 2, which is another plane layer made with 1 oz. copper and is 0.0014 in. thick. Another prepreg sublayer constituting two sheets that are 0.0091 in. thick forms part of inner layer 2. The final layer, the bottom layer, is also 0.0014 in. thick, and is a signal layer as well. Interconnects are soldered and placed on the top and bottom layers.


4-layer PCB has two stacking forms


The standard 4-layer PCB stack is shown below, and GND and VCC can be switched according to the layer with more signals.


The standard 4-layer PCB stack



If you don't want to connect all the ground pins through the hole, there will be different stacks and wide power routing on the signal plane.

4-layer PCB stack another type

For the following reasons, this may be a better stack to use a four-layer PCB:



  • The signal layer is adjacent to the plane. The signal running on the reference plane (whose voltage is exactly at the VCC) will still return on the reference plane.
  • Signal layers are tightly coupled to their adjacent planes.
  • The ground surface can be used as a shield for the internal signal layer. You will get better results, so that your plane height is as low as possible.
  • Multiple grounding layers reduce the grounding (reference plane) impedance of PCB and common mode radiation.

When the high-speed signal changes the reference plane, there should be a nearby path for its return current to move between the two reference planes. Using two horizons, you can do this by connecting two planes directly to a single channel. For grounding and power layers, the connection must be made through capacitors, which usually require two through-holes and one capacitor. This means worse signal integrity and more circuit board occupancy. On the other hand, having a power plane can reduce the voltage drop on the power rail, thereby releasing the space on the signal layer.

PCB Board Thickness

4 LAYER 0.8 MM STANDARD BUILD

4 LAYER 0.8 MM STANDARD BUILD

4 LAYER 1.6 MM STANDARD BUILD

4 LAYER 1.6 MM STANDARD BUILD


0.4mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.6mm, 2.0mm, 2.4mm, Please contact us if your board exceeds these.




4 layer PCB Prototype


4-layer circuit board prototyping refers to the trial production of printed circuit boards before mass production. It is mainly used for electronic engineers to design circuits and complete PCB Layout, then to carry out small-scale trial production process to the factory, that is, proofing PCB. The production quantity of four-ply proofing generally has no specific boundaries. Generally, engineers call it proofing before product design has not been confirmed and test has been completed.

Notices for proofing of four-layer circuit boards

The precautions for the production of four-layer PCB samples generally include two groups, one is the Engineer group, the other is the PCB sample manufacturer.

As a group of engineers, the matters needing attention in proofing are as follows:

1. Choose proofing quantity carefully to control cost effectively.
2. Specially confirm device packaging to avoid proofing failure due to packaging errors.
3. Conduct comprehensive electrical inspection to improve the electrical performance of PCB board.
4. Make good signal integrity layout, reduce noise and improve PCB stability.

As a manufacturer of four-layer circuit boards, the precautions are as follows:


1. Check PCB files carefully to avoid data problems.
2. Conduct process approval in an all-round way and process configuration with self-manufacturer.
3. Control production quantity, reduce cost and maintain quality.
4. Communicate with customers who need samples to prevent accidents in advance.



4 layer PCB price and cost


We specialize in Quick Turn PCB services with an industry leading turnaround time as fast as 24 hours. Three low-cost options for a small number of PCB prototyping needs. At the same time, we also provided Flexible PCB , Rigid-Flex PCB, Metal Core PCB, High-TG PCB, Aluminum PCB , PCB Stencils, PCB Assembly Services and so on. Using the same high-tech equipment as our full-service PCB, it can be manufactured quickly and with virtually no limits.


Cost of four layer PCB is higher than double sided PCB because of complexity of design and higher sensitivity. The better quality of signals, achieved by reducing distortion and propagation levels, is also a factor. Because of the higher levels of signal integrity and reduced interference levels, more manufacturers prefer four layer PCB.




4 layer PCB manufacturing


We provide a full range of PCB functions to meet all your PCB needs. At present, we accept five PCB file formats (gerber file,.Pcb,.Pcbdoc.cam or.brd file format) for PCB manufacturing. But if you design a circuit board using Sprint-Layout software, you can send the. LAy6 file to us to manually generate the Gerber file.

JingHongyi PCB can provide you with multi-layer PCB board that meets RoHS standard. With laminated material, it can match high temperature in assembly process. It is important to remember that some lead-free assembly processes will require laminated substrates to withstand temperatures exceeding 260 degrees Celsius or 500 degrees Fahrenheit over a longer period of time. To solve this problem, we have high temperature laminates in stock, so that our customers can meet the higher temperature cycle requirements of some lead-free assembly applications.

Min. Order Quantity: 1 pcs
Material: FR-4
Finished Copper: 1oz/2oz/3oz(35μm/70μm/105μm)
Inner Layer Copper Thickness:1oz/1.5oz(35μm/50μm)
Silkscreen: White, Black, None
Surface Finishing: HASL with lead, HASL lead free, Immersion gold, Hard Gold ,OSP...
Shape: Custom Shape




100% Quality control


When making circuit boards, and after they are finished, we will test and inspect them strictly to ensure that the product reaches 100% eligibility rate. Preferential prices and higher quality have always been our constant pursuit:

  • E-test
  • AOI - Testing (Automatic Optical Detection)
  • X-ray (check multi-layer registration accuracy)
  • CCD-camera controlled drilling
  • Impedance control


4 Layer PCB
Four Layer PCB


Videos for 4 layer PCB design and manufacturing

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JingHongYi PCB (HK) Co., Limited , https://www.pcbjhy.com